Seriously, a phalanx is only as good as the discipline of the soldiers holding it together. Anything that can break up the formation is your aim: Catapult, rough ground/trenches, oil and fire. As Eddings once wrote, it's hard to concentrate on anything when you are on fire.

Choose the fighting ground and make them come to you, up hill and rough ground is good, woods are better. Use flanking movements and archers to get them to make formation changes, the shield and armour are heavy - make them sweat! Use fire and smoke, set fire to grasslands etc., oil is your friend. Attack their feet: snares, pitfalls, rocks, logs, calitropes.

In the battle of Lechaeum the Athenian general Iphicrates took advantage of the fact that a Spartan hoplite phalanx operating near Corinth was moving in the open field without the protection of any missile-throwing troops. He decided to ambush it with his force of peltasts. By launching repeated hit-and-run attacks against the Spartan formation, Iphicrates and his men were able to wear the Spartans down, eventually routing them and killing just under half. This marked the first recorded occasion in ancient Greek military history on which a force entirely made up of peltasts had defeated a force of hoplites.

Why rabid rats? That's too sadistic... mental factors like fear can do the trick. It's hard to even gather pestilential rats... and I bet they never even inhabited cities until Rome built her aqueducts.

the real way the Phalanx became obsolete was through countering it with more mobile units

over time the discipline and training of the troops declined, they became weaker on the flanks and they lacked the coordination and mobility to deal with skirmishing flankers

the discipline and coordination of the phalanx relied upon instilling in its members that discipline and coordination would make them invulnerable and once this began to be countered they lost that sense and the phalanx became just a bunch of heavy infantry with arrows sticking out of their corpses

lighter infantry were also less expensive to train and equip, it was easier to build a unit that could undo a phalanx than to try and counter it with a phalanx of your own

You could throw a hornet's nest in the middle and send them scattering. Also, those rolling balls of fire like in the movie troy. I bet they really used stuff like that. It's simple and would scare the crap outta me.

That only works in movies. A hornet nest is neutralized by throwing a blanket over it. Burning balls of straw, brushes etc. can be warded off with the spears and you can only use them when fighting downhill.

In Rome Total War, phalanx units are excellent versus cavalry charges, as long as you keep the phalanx between the unit and the horses. However, you can outflank them rather easily because a unit is slow in phalanx formation and the AI can be confused rather easily. There are a few scenarios in which a phalanx is deadly (or Swiss pikemen), e.g. guarding a bridge or town gate from enemies with weaker or less missile power and artillery.

any kind of fixed formation with pointy stuff sticking out will deter horses, they don't like charging into big pointy things, its the same reason armies fixed bayonets and formed square two thousand years later

A phalanx normally would only be defeated in open battle through maneuver, which is how the rudimentary concept of flanking really came into being. You would want to avoid the long, pointy bits, so eventually units in a one-on-one phalanx battle would rotate. Maneuver was the weakness inherent in trying to carry a longer pointy bit (sarisa) than the other guy; you get kind of worn out trying to hit someone with a 6 meter long sharpened pole.

Since we (as in you guys) inject it into every other feckin' thread, why not here? I've read more than once that despite all the pro-queer propaganda (and not from the normally risible Conservapedia), the Greeks (and later the Romans) were remarkably intolerant towards homosexuality in the context of social structure. In other words, a lot of what we now consider Greek normality was actually anti-Greek propaganda spread to discredit their historical significance.

Pederasty and such was apparently considered great for fun and games, particularly of the student-teacher variety, but upon achieving adulthood you damn well better settle down with a stodgy wife (who was barely let out-of-doors) and do some spawning, Pronto. Kind of reminds me of "modern" Middle Eastern Islam, where pederasty is commonplace and surreptitiously condoned, but open queer behavior is death penalty material.